This application claim the benefit of Provisional application Ser. No. 60/022,405, filed Jul. 30, 1996.
1. Field of the Invention
This invention relates to a device that controls a garage door opener so that it automatically closes an open garage door after the lapse of a predetermined amount of time.
2. Description of the Prior Art
Devices that open and close garage doors are commonly referred to as garage door openers. That terminology will sometimes be used herein, although it should be understood that the term garage door opener refers to a garage door closer as well.
There are two different types of switches for actuating a garage door opener. The first type is a normally open, momentary contact (push button) switch that is manually operated; it is permanently mounted on a structural wall at a convenient location. The second type is actuated by a portable, very high frequency, short range transmitter that is typically kept in a vehicle. The transmitter sends an encoded signal that is received and decoded by a receiver mounted in a garage; the receiver includes an antenna and a decoder and generates a signal that actuates a mechanical means for opening or closing the door upon reception of an authorized signal.
The mechanical means is typically a reversible electric motor. A nonreversible motor may also be used if modified to include clutches or other suitable mechanical means that enable it to perform the functions of a reversible motor.
Typically, limit switches are provided in a garage door opener controller means to shut down the motor when the door reaches its fully opened or fully closed position. Moreover, the controller means includes a door direction reversing means to reverse the direction of door travel at the conclusion of each door movement, i.e., when a door has been fully opened and the motor shut off, the controller means reverses the direction of the means controlling the direction of door travel so that the next motor activation results in door closing, and vice versa.
Additionally, most garage door openers include safety means to open the door when the mechanism is in its door-closing mode if an obstacle is encountered as the door lowers.
Devices have also been patented for closing, upon the expiration of a predetermined amount of time, garages doors that have been left open inadvertently. This feature enhances the security of the garage and of the attached dwelling, if any, i.e., it helps prevent theft and burglaries of the type commonly associated with open garage doors. It also saves a homeowner from interrupting a trip to make a return visit to the house just to check on the position of the garage door.
The needed device should have a structure that makes it economically feasible to include it in new garage door openers as a part of their original equipment. It should also be provided as a package suitable for retrofit applications as well.
However, in view of the art considered as a whole at the time the present invention was made, it was not obvious to those of ordinary skill in this art how the needed garage door opener could be provided.